This application relates to the art of pressure cutoffs and pressure relief valves and, more particularly, to a unitary assembly that performs the combined functions of a pressure cutoff and a pressure relief valve. The invention is particularly applicable for use with air conditioner compressors and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and can be used for regulating and relieving pressure in other devices.
Air conditioner compressors are commonly provided with a pressure cutoff switch for turning the compressor off when a predetermined pressure is reached. When the pressure subsequently falls below the predetermined pressure, the compressor is again turned on. The pressure cutoff cycles the compressor off during high pressure conditions and back to on when the pressure is again at a normal level.
In the event of a malfunction, such as an electrical failure or externally applied heat, the pressure cutoff may not turn the compressor off. The pressure will then continue to build and could result in explosion of the air conditioning system. To prevent such an explosion, it is common to provide a pressure relief valve for venting the pressure when it exceeds a predetermined value.
It would be desirable to have a unitary assembly for performing the dual functions of providing a pressure cutoff and a pressure relief valve in a reliable and simplified manner.